This specification relates to classifying queries.
Internet search engines aim to identify resources, e.g., web pages, images, text documents, multimedia context, that are relevant to a user's needs and to present information about the resources in a manner that is most useful to the user. Internet search engines return a set of search results in response to a user submitted query. Conventionally, each search result identifies a particular resource responsive to the query. If a user is dissatisfied with the search results returned for a query, the user can attempt to refine the original query to better match the user's needs.